This invention relates to rain gauges.
Rain gauges are known that include a rain collector and large numerals and/or words indicating the height of the water in the rain collector. In this class of rain gauges, the rain collector has indications, such as numerals and lines to indicate the gradations of water height and the numerals are large enough to be read from several yards away. An adjusting mechanism referred to herein as an interface is mounted to the top of the collector to collect water from a wider area than the cross section of the rain collector so that the water rises at a multiple of the rainfall per square inch but in proportion to it so there is room for larger numerals on the rain collector itself to indicate the amount of rain per square inch that has fallen. The rain collector is a tube with a plug at the bottom and the interface at the top. The tube is removably mounted to a bracket for ease in fastening to an upright surface. This type of rain gauge is disclosed in U.S. Pat. No. 5,038,606 granted Aug. 13, 1991, to Robert C. Geschwender, et al. A float aids in seeing the height of the rain water in the rain collector.
While this prior art rain gauge operates well, there are several aspects of its operation that can be improved upon, such as: (1) it is somewhat difficult to read the height of the rain water in the collector from a distance, particularly at night; (2) the float is not as visible as desired; (3) to prevent leakage, an “O” ring is used, which increases the expense of manufacture or special costly efforts are needed to create a permanent water tight fit with the plug at the bottom of the rain collector; and (4) under some circumstances such as a heavy rain, the rain water overflows the interface.
In another type of prior art rain gauge, the collector is a uniform cylindrical tube which receives rain through the open top so that the rain rises in the cylindrical rain container in proportion to the inches of rainfall. The cylindrical rain container is mounted against a flat surface that has lines printed on it at intervals indicating the inches of rainfall. As the rain rises in the cylindrical rain container, it magnifies the lines seen through the water out of proportion to any distortion of the lines behind the part of the cylindrical rain container not having water to indicate with a distinctive line the level of rain. On the flat card, the inches of rain are indicated. This prior art rain gauge has the disadvantages of still being difficult to see from a distance because of its non-expanded vertical scale and the narrow diameter of the cylindrical rain container and because, in fog or at night, the numerals are difficult to read.